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ARRT Board Radiopharmacy

Terms in this set (39)

Discuss active transport as a method of localization for pharmaceuticals
Active transport is defined as the utilization of a normal metabolic pathway to allow the radiopharmaceutical to penetrate the cell membrane and incorporate itself into the cell

and example of active transport would be fine word imaging because iodine is incorporated into the thyroid via active transport
iodine becomes trapped in the thyroid is converted into T3 and T4
Define effective half life
Defined as the amount of time required to reduce the quantity of a substance in the body one both physical and biological half 's are taken into consideration
affective half-life combines the action of radioactive decay and natural elimination

1. 1. +. 1
—. — —
t eff = t biol. t phys
Define physical half life
Is the amount of time it takes for the original number of atoms in a radioactive sample to be reduced by 50%
each radioactive isotope has a different rate at the K or half-life however the rate of decay for each radio isotope is constant and cannot be altered by outside influences such as temperature or pressure
Discuss capillary blockade as a method of localization for radio-pharmaceuticals
Capillary blockage occurs when radioactive particles are injected IV into a patient and the radioactive particles become trapped in the capillary beds of the patient
this motive uptake is primarily associated with pulmonary perfusion imaging in which Tc-99m MAA is injected IV and the tech 99M MAA particles become trapped in the capillaries of the lungs
tech 99MM MAA particles must have sizes ranging from 10 MM to 90 MM allowing for capillary blockage in lungs
Define biological half life
-Defined as the amount of time it takes the body to eliminate half the quantity of any substance not just radioactivity
-The bodies main methods of eliminating substances are genitourinary excretion, gastrointestinal excretion, exhalation of perspiration
Explain the production of Auger electrons
-Auger electrons are produced when an inner shell electron is released from its orbit leaving a vacancy
-when there is a vacancy on an inner shell outer shell electrons adjust and move closer to the core filling the vacancy
-every time an electron moves to a different shell energy is released
-sometimes the energy is released in the form of a photon
-an auger electron is one that absorbs energy and is subsequently released from the atom
Discuss pair production
-Pair production occurs when a GammaRay reaches the facility of a nucleus
-The energy of the GammaRay is totally absorbed by the electron field of the nucleus the fielding the production of a beta particle and a positron
-pair production will only occur if the GammaRay has a minimal energy of 1.0 to 2 MEV
-The beta particle travels until it is incorporated into an atom or ask a free electron
-The positron inevitably collides with an electron resulting in annihilation of both particles in the omission of two cameras with 511 KEV of energy
Discuss compton scatter
-Compton scatter occurs when a GammaRay interacts with the free or loosely bound electron
-some of the energy from the GammaRay is absorbed into the electron
-if they collide head on the majority of the gamma rays energy will be transferred to the electron
-if the collision occurs at different angles a lesser amount of energy will be transferred from the GammaRay to the electron
Compton's got a removes the electron from its orbit end result in a reduced energy GammaRay
Discuss gamma decay
Atomic number of the parent and daughter atoms are identical
in order for the nucleus to remove itself from the excited state in return to the stable ground state it must emit energy
The energy omitted from these nuclei is in the form of photons referred to as gamma rays
For isotopes that he was gamma decay of photons that are admitted contain the same energy and ionization properties
Explain the photoelectric effect
Occurs when a GammaRay interacts with an electron in an inner orbit
during this interaction the energy from the GammaRay is totally absorbed by the inner orbit electron
The electron that absorbs the gamma rate is referred to as a photo electron
The energy of the photoelectron is equal to the energy of the GammaRay minus the binding energy of the electron needed to remain in its orbit
due to the vacancy of an inner orbit electron outer orbit electrons will drop down to fill the space left by the photo electron in a series of x-rays will be admitted from every electron that changes orbit
Define Bremsstrahlung
Is the production of electromagnetic radiation caused by the sudden deceleration or deflection of a fast moving charged particle when to collides with another charged particle
This phenomenon occurs primarily when beta particles Pass near an atomic nucleus
The beta particles in atomic nucleus is are attracted to each other due to opposite electrical charge
The beta particles change direction slow down and move toward the atomic nucleus
The slowing of the beta particles cause a reduction of kinetic energy within the particles
Kinetic energy is lost in the form of x-rays the energy of the x-ray is equal to the amount of kinetic energy lost by the beta particles
Discuss beta decay
Is is a radioactive decay process in which an unstable Adam admits a beta particle in order to achieve stability

this form of decay can result in two different particles being omitted either an electron or a positron

if an electron is emitted the particle is referred to as a beta minus
if a positron is emitted the particle is referred to as a beta plus
invader minus decay the atomic number of the daughter atom increases by one
Beta plus decay, the atomic number of the daughter atom decreases by one
Discuss the significance of the Mo-99/ Tc-99m breakthrough test
Mo-99 is the parent molecule of TC-99M
The current regulations state that every time a MO-99 generator is a looted the breakthrough test must be performed to evaluate the purity of TC-99M
The Tc-99m that is alluded must not contain greater than .15 µCi of MO-99 per one mCi of Tc-99m
Discuss chemisorption as a method of localization for radio-pharmaceuticals
Is defined as the chemical binder of a radiopharmaceutical to the surface of another substance
and example would be when MDP is injected IV and binds to the hydroxyapatite crystals of the bone
acute myocardial infarction imaging is also performed using chemabsorption
TC 99MPYP similar to MDP binds to the hydroxyapatite crystals so infarction imaging can be obtained
Discuss phagocytosis as a method of localization for radio-pharmaceuticals
Engulfment of solid particles by cells known as phagocytes
Kupffer cells located in the liver act as phagocytes for uptake of radioactive particles
IV injection of tech 99M sulfur colloid is localized in the liver due to phagocytosis
in order for this to occur the average particle size of tech 99M sulfur colloid must be between .1 and 2.0 mm since the average capillary size in the liver is 7 mm
List the characteristics of radio-pharmaceutical kit preparation that must be documented.
for each radioactive kit that is prepared
*date and time of the preparation
*the lot number of the pharmaceutical
*the expiration date of the pharmaceutical
*the activity of the preparation
* the volume of the preparation in
*the concentration of the preparation must be documented to be in compliance with NRC regulations
Explain the oxidation/ reduction in radio-pharmaceutical kit preparation.
TC 99M needs to be in a reduced oxidation state in order to bind effectively with the radiopharmaceutical Most radiopharmaceuticals require the Stannous (tin) ion in order to reduce the Tc 99m
if the compounded radiopharmaceutical is exposed to oxygen the compound may have impurities
if oxidation occurs the compound NaTc04 may result
if the compound becomes hydrolyzed liver uptake may be visible on skeletal imaging due to the tech acting as a colloid
Discuss compartmental localization as a method of localization for radio-pharmaceuticals
Involves placing a radiopharmaceutical in a space and maintaining in in that space long enough to perform imaging
And example of this is pulmonary ventilation imaging which is performed via and healing tech 99M DTPA or xenon 133 gas directly into the lungs
Cisternograms use compartmentalize localization to via indium 111 DTPA administration directly into the cerebral spinal fluid by lumbar puncture
Discuss the procedure for 3- phase skeletal imaging
Position the patient under the camera with the affected area position in the field of view
The flow phase of the acquisition should be obtained via dynamic imaging for a minimum of 10 frames at five seconds per frame
Immediately following the flow phase the blood pool image should be acquired for approximately 500,000 counts
at this point the three hour week period has begun to allow proper absorption of tech 99M MDP into the bones
Once a three hour wait. It's complete delete imaging is preferred at similar parameters as the blood pool face to complete the third phase of the procedure
Explain the patient prep for skeletal imaging
There is virtually no patient prep for skeletal imaging prior to injection once injection is given approximately three hours are needed to allow for proper absorption of the radioisotope into the bones
throughout the way. Patient is instructed to drink plenty of fluids
Discuss the indications for a whole body skeletal imaging
Routinely performed for high-risk patient with malignant tumors that are known to metastasized to the bones tumors located in the breast lung and prostate are the most frequent primary cancers in which skeleton image is useful
frequently performed following in evaluated alkaline phosphate blood results as a routine follow up to therapeutic regimen such as radiation therapy and chemotherapy
Whole body imaging may also be performed for petition pumping that is unexplained my other modalities
Explain the imaging procedure for a while body skeletal imaging
Once the patient has completed the three hour wait. Following the IV administration of MDP the imaging can be acquired
Immediately prior to skeletal imaging the patient has asked to void completely
Instruct the patient lying supine position on the imaging table
Center the patient
Using a low energy high resolution collimator adjust the detector so it is close to the patient possible without touching him or her
set the scan speed of the gamma camera to approximately 12 seconds per CM
speed will acquire the whole body image in approximately 20 minutes
Discuss the equipment prep for a skeletal SPECT imaging
ACOR evaluation should be performed on a weekly basis

A bar phantom image and in some Cases a tomographic phantom image should be acquired on a monthly basis
The camera should be equipped with a low energy high resolution collimator
Detector should be programmed for a 360° rotation as close to the patient as possible
Respect images should be acquired using at 128 x 1 28 matrix the acquisition should be set for 64 frames and a minimum of 20 seconds per frame
Discuss the clinical indications for 3 phase skeletal imaging
Osteomyelitis
a vascular necrosis
trauma
soft tissue abnormalities (cellulitis)
to detect a bone involvement that may be present with this condition
Discuss the indications and procedure for preforming radionuclide cerebrospinal fluid imaging. (cisternogram)
Cisternography is performed for the assessment of normal and abnormal drainage of cerebral spinal fluid evaluation of Hydro syphilis and localization of leaking cerebral spinal fluid in the ears or nose
administration of IN 111 DTPA a lumbar puncture by a licensed radiologist
immediately following the lumbar puncture a static image should be obtained to ensure proper administration of the isotope
Cereal static images are then performed in the anterior posterior right lateral and left lateral positions at two 624 in 48 hours post injection
Discuss the indications and procedure for preforming Ga-67 imaging.
Used to evaluate infections and inflammatory processes such as fever of unknown origin respiratory infection such as tuberculosis acquired immune deficiency syndrome and tumors associated with lymphoma
The study is obtained following IV injection of 5 to 10 mCi of GA 67 citrate
if evaluating for infection in early set of images are obtained at six hours post injection
if evaluating tumors imaging is performed later at 48 to 72 hours post injection
During each set of images a whole body image should be obtained

static images of the head chest abdomen and pelvis are also obtain during each imaging session
all static images should be obtained for 1000k Countns
The energies of the photons of G8 67 or 180 keg and 296KEV so medium energy collimator should be used for all imaging acquisitions
Explain the in-vitro method for tagging red blood cells for MUGA or GI bleeding procedures.
Tagging occurs entirely outside the body

ultra tag is the primary pharmaceutical used to tag red blood cells
The procedure for in vitro tagging requires two IV injections
initially five ML's of blood is withdrawn from the patient and 1 to 3 ML is then deposited into the ultra tag kit vile
The blood and ultra tag combination should be allowed to mix for approximately five minutes with occasional gentle shaking of the vile
Once the five minute mix is complete syringe one of the ultra tag leveling kit is injected into the vile containing blood and ultra tag and gently shaken
Immediately after syringe one has been injected into the mixture add syringe to to the mixture and gently swirl
immediately after syringe one has been injected into the mixture add syringe 2 to the mixture and gently swirl
once syringe 2 has been injected add 25 to 35 mCi of tc 99M pertechnetate to the mixture and allow it to sit for 20 minutes with occasional gentle shaking
wants to 20 minute time. Has elapsed administer the entire make sure to the patient via IV injection no patient prep is required for the in vitro tagging of red blood cells
Discuss the similarities and differences in preforming infection imaging with In-111 leukocytes and Tc-99m labeled leukocytes
The procedure of tagging the white cells is the same for either isotope
The identical amount of blood is withdrawn from the patient in the isotope is administered via IV injection
Activities of the isotopes are different however with I N1 11 label to leukocytes yielding approximately .5 mCi whereas TC 99M labeled leukocytes Yeild approximately 20 mCi
because of the higher activity the latter are preferred when imaging the extremities
In-111 labeled Leukocytes are preferred when assessing abdominal or kidney infection
the infection may be masked if Tc 99m is used due to genitourinary excretion of the isotope
Discuss the role of adenosine in cardiac stress testing.
Pharmaceutical that may be used to perform stress testing and patients who are unable to exercise on a treadmill or stationary bike
acts as a vasodilator in the body which means it increases the diameter of the blood vessels in order to increase blood flow to all parts of the body
Denison simulates exercise in the body and myocardial perfusion can be accurately assessed after IV infusion of adenosine
Discuss the administration and biodistribution of Tc-99m MDP with respect to skeletal imaging.
TC 99M methyl diphosphonate is the radiopharmaceutical most commonly chosen for skeletal imaging
TC 99MDP is administered to the patient via IV injection
20-30 mCi is administered
MDP localizes in the bones via chemisorption.
chemisorption is the process in which the radiotracer becomes chemically bound to the hydroxyapatite structures of the bone
Discuss the indications and prcedure for preforming a brain SPECT study
Used to evaluate cerebrovascular disorders such as hemorrhages and TIA And evaluate psychiatric Disorders like dementia
evaluate head trauma and epilepsy
obtain the following IV administration of TC 99M HMPAO
SPECT images are obtained by placing the patient on the imaging table in a supine position
acquisition parameters are a complete 360° rotation for 64 frames at an imaging time that would allow approximately 200,000 counts per frame at 128 x 1 28 matrix should be used for the acquisition
List the indications for a PET scan of the brain
A brain pet can be obtained to assess cerebral infarct's differentiate depression from dementia evaluate disorders of the basal ganglia such as Parkinson's disease and Huntington's disease localized epileptic triggerpoints and evaluate the location extent and reoccurrence of brain tumors
May also be used to evaluate the effectiveness of therapeutic drugs used to treat mental illness
Discuss the indications and procedure for preforming a brain death study.
Used to confirm brain death and patients who present with unresponsive, fixed and dilated pupils and electroencephalogram
The procedure is performed by IV injection of TC 99M pertechnatate TC 99M DTPA or TC 99M bicisate
A dynamic flow study is done initially for approximately 90 seconds at a rate of two seconds per frame
approximately 15 minutes following the dynamic acquisition planer images are taken in the anterior posterior right lateral and left lateral positions at 500,000 counts per projection
Discuss any side effects a patient may experience during intravenous administration of adenosine
A patient may experience a warm flushed feeling all over the body
patient experience shortness of breath sweating coughing and a decrease in blood pressure during the infusion
patient experience is high degree AV heart block
episodes of heart block are usually transient and resolves spontaneously during the infusion
Discuss the procedure for preforming a MUGA scan
Obtain to assess the contractility of the left ventricle
Study is of great importance for patients who are undergoing chemotherapy treatments that may be cardiotoxic
obtained by tagging red blood cells with TC 99 Pertechnatate
procedure can be performed using either in vevo or in vitro red blood cells tagging techniques
once the red blood cells have been tagged with tech 99M pertechnatate imaging may be performed
A mega scan involves the acquisition of three gated images of the heart at anterior 45° and left lateral projections
prior to imaging the patient must be connected to a heart monitor so getting in wall motion can be assessed
Discuss the indications and procedure for thallium- 201 myocardial viability imaging
Myocardial viability imaging with TL201 is often performed to assess the presence or extent of myocardial damage following in myocardial infarction
used to assess patency of the coronary arteries immediately after cardiac bypass surgery
The procedure is only performed with the patient in a resting state viability imaging is not done during stress testing
The patient is injected with 2 to 4 mCi of TL201 intravenously
immediately following administration of TL201 aspect myocardial perfusion image is obtained
additional SPECT myocardial perfusion images are obtained at six hours and 24 hours post injection
The delete images are used to determine if the area of the myocardial infarction will absorb TL201 overtime which will determine myocardial viability
Discuss the role of dobutamine in cardiac stress testing
Is a pharmaceutical that may be used to perform stress testing in patients who are unable to exercise on a treadmill or stationary bike
dobutamine is commonly used to improve cardiac function in patients with heart failure in cardiogenic shock

dobutamine enables the heart rate and blood pressure to increase to the point that a diagnostic stress test can be obtained an accurate myocardial perfusion imaging can't be performed
Discuss patient prep for myocardial stress testing
The patient is instructed to have nothing by mouth for a minimum of four hours this is to ensure the heart is the most metabolically active organ in the body and the maximum amount of isotope will be taken up by the heart and not the stomach
for treadmill and debridement and do stress test patients are instructed to discontinue any beta blocker medications beta blockers make it difficult to achieve max heart rate
for adenosine and record Denison and do stress test patients are instructed to discontinue any medications that contain theophylline and refrain from any food or beverage that may contain caffeine
Diabetic patient should have their medications and Diaz adjusted by their primary care physician prior to cardiac stress testing
Explain the in- vivo method of tagging red blood cells for MUGA or Gi bleed procedures.
With the in vivo method tagging occurs entirely inside the body
-this method requires two IV injections -initially the patient is injected with 10 MG of cold PYP
-the PYP must circulate inside the body for approximately 20 minutes to adequately tag the red blood cells
-after 20 minutes the patient is injected IV with 20 to 30 mCi of tech pertechnatate
-The isotope should circulate in the body for approximately 10 minutes before imaging may occur
- no patient prep is required for in vivo tagging of red blood cells
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